Indian Army — non receipt of appointment letter

Address:

Postal Colony, Koraput, Odisha, 764020

Sir, i was selected for material asst post in cod jabalpur in jun 2017 but not getting appointment letter even now, despite completing all joining formalities successfully in dec 2017 itself. I received letter in jan stating that extension of nac received and appointment letter will be issued shortly. Some selected persons have already joined few weeks back. But i have not received appointment letter yet. Also no communication for the inordinate delay. Kind help sir.
Goutam ghosh